What to know
Tomioka (富岡) is a city in southwestern Gunma Prefecture that houses Japan's first modern silk factory, founded in 1872. The Tomioka Silk Mill became a model for other mills nationwide as Japan modernized its silk industry during the Meiji Period, a time of sweeping reforms aimed at catching up with Western powers. For decades, the mill helped make textiles Japan's leading industry, fueling economic growth.
As Japan's oldest modern silk-reeling factory, the Tomioka Silk Mill was also among the world's largest when built. Its innovations turned raw silk into a major export, and Tomioka silk earned a global reputation for high quality. The well-preserved original buildings form the centerpiece of four silk-related sites in Gunma Prefecture that were inscribed as a UNESCO World Heritage Site in 2014.
The other three sites are in nearby cities: the Tajima Yahei Sericulture Farm, which advanced silkworm egg production; the Arafune Cold Storage, whose naturally cool environment allowed multiple harvests by storing eggs; and the Takayama-sha Sericulture School, which improved the process of raising silkworms into cocoons for processing at the Tomioka mill.
